Methods of operation of an RFID tag assembly for use in a timed event

ABSTRACT

A method of operating a radio frequency identification (RFID) tag assembly in a timed event including in the radio frequency identification (RFID) tag assembly having a spacer having a thickness of between about 0.125 inches and about 0.5 inches, placing the RFID tag assembly in a position relative to the operating surface of the body a minimum spaced apart distance, receiving at the first side of the two sided planar antenna a first portion of the radio frequency energy as direct energy as transmitted from the antenna of the base station transceiver, receiving at the second side of the two-sided planar antenna a second portion of the radio frequency energy as indirect energy as transmitted from the base station transceiver antenna, the second portion of the radio frequency energy being received at the predetermined operating frequency, and processing the received first and second portions of the radio frequency energy.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Continuation of U.S. application Ser. No.14/071,480, that was filed on Nov. 4, 2013, and which is now U.S. Pat.No. 9,515,391 as issued on Dec. 6, 2016, which was a Continuation ofU.S. National Phase patent application Ser. No. 13/129,771 filed May 17,2011 (Now U.S. Pat. No. 8,576,050 issued Nov. 5, 2013); which was a 371National Phase of International Application No. PCT/US10/22559, filedJan. 29, 2010 and entitled HARSH OPERATING ENVIRONMENT RFID TAGASSEMBLIES AND METHODS. The disclosures of the above applications areincorporated herein by reference.

FIELD

The present disclosure relates to radio frequency identification(“RFID”) tags, and more specifically, to assemblies and methods for RFIDtags for use in a time event.

BACKGROUND

The statements in this section merely provide background informationrelated to the present disclosure and may not constitute prior art.

Typical RFID tags are not designed for use under harsh conditions. Theyare unsuitable for use in harsh conditions because of numerous factorsincluding, for example, limited tag read ranges when used in harshenvironmental conditions, the lack of protective design for the tagwhich increases the potential for damage due to harsh conditions, and areduced ability to communicate with a tag reader when the tag is mountednear a radio frequency (RF) absorbing medium, such as the human body.

For example, contamination by water or other foreign materials, such asdirt or mud, that comes in contact with or in very close proximity to anRFID tag can adversely impact the operational characteristics. These cannegatively impact the strength of the energy received by the RFID tag,which in turn negatively impacts the available power at the tag.Physical shock or jolts can also damage an RFID tag that can negativelyimpact the communicative ability of the RFID tag. By way of example,RFID tags, such as a passive RFID tag, are increasingly used for timingin many types of participants in racing events. However, many eventssuch as adventure races, motocross, mountain biking, swimming, ortriathlons, to name just a few, present a harsh environment thatnegatively affect the survivability and operation of the RFID tag foruse in timing a participant.

Additionally, when an RFID tag is placed near a medium that absorbs RFenergy, the operational ability and/or operating range of the RFID tagcan be impacted. In fact, when an RFID tag is placed proximate to ahuman body or on or near a vehicle such as a mountain bike, RFabsorption can significantly limit the operation of the RFID tag.

SUMMARY

The inventor hereof has identified the need and advantages of providingan assembly for an RFID tag having an extended tag operating range thatfunctions well when positioned in close proximity to a structure thatabsorbs RF energy and/or that is configured to operate in a variety ofoperating environments including those that may be harsh. The inventorhereof has succeeded at designing assemblies and methods for operatingan RFID tag that is capable of use in such operating environmentsincluding placement on a runner or vehicle during a race, by way ofexample.

According to one aspect, a radio frequency identification (RFID) tagassembly including an RFID semiconductor chip, a conductor and anantenna. The RFID semiconductor chip has an antenna interface mounted ona mounting surface of a mounting substrate and a predetermined operatingfrequency. The conductor is electrically coupled to the antennainterface of the RFID semiconductor chip. The antenna is electricallycoupled to the conductor and includes a first radiating element lying ina first plane and a second radiating element lying in a second plane.The second plane is at an angle relative to the first plane.

According to another aspect, a radio frequency identification (RFID) tagassembly includes an RFID semiconductor chip having an antenna interfacemounted on a mounting surface of a mounting substrate and has apredetermined operating frequency. The assembly includes a conductorelectrically coupled to the antenna interface of the RFID semiconductorchip that is mounted on the mounting surface. The assembly also includesan antenna that is electrically coupled to the conductor. The antennahas a first radiating element lying in a first plane and a secondradiating element lying in a second plane. The second plane is at anangle relative to the first plane. The first radiating element haslength less than about ¼ of a wavelength of the predetermined operatingfrequency and the second radiating element has a length less than about¼ of the wavelength of the predetermined operating frequency.

According to still another aspect, a radio frequency identification(RFID) tag assembly including an RFID semiconductor chip having anantenna interface mounted on a mounting surface of a mounting substrateand having a predetermined operating frequency. A conductor iselectrically coupled to the antenna interface of the RFID semiconductorchip and is formed on the mounting surface of the mounting substrate. Anantenna is electrically coupled to the conductor and has a firstradiating element lying in a first plane and a second radiating elementlying in a second plane. The second plane being at an angle relative tothe first plane. The assembly includes an enclosure having a bodydefining a cavity with a closed end and an opening. The cavity isdimensioned for receiving the mounting substrate with the RFIDsemiconductor chip, the conductor, and the first and second radiatingelements. The mounting substrate is positioned proximate to the closedend of the cavity. The assembly further includes a seal for closing theopening and sealing the cavity.

According to another aspect, a radio frequency identification (RFID) tagassembly includes means for processing received radio frequencyidentification requests and generating responses to such requests andmeans for receiving and transmitting radio frequency energy in a firstplane at a predetermined operating frequency between the means forprocessing and a remote transceiver. The assembly also includes meansfor receiving and transmitting radio frequency energy in a second planeat a predetermined operating frequency between the means for processingand a remote transceiver, the second plane being at an angle relative tothe first plane. The assembly further includes an enclosure having abody defining a cavity with a closed end and an opening. The cavity isdimensioned to receive and enclose the means for processing and meansfor receiving and transmitting in a first plane and means for receivingand transmitting in a second plane. The assembly also includes means forclosing and sealing the cavity of the enclosure including the means forprocessing and means for receiving and transmitting in a first plane andmeans for receiving and transmitting in a second plane.

According to another aspect, a method of operating a radio frequencyidentification (RFID) tag assembly including receiving at a firstradiating element in a first plane of an antenna coupled to an RFIDsemiconductor chip a first portion of radio frequency energy transmittedfrom an antenna associated with a base station transceiver positionedremote from the RFID tag assembly. The radio frequency energy being at apredetermined operating frequency. The method also including receivingat a second radiating element in a second plane of the antenna coupledto the RFID semiconductor chip a second portion of the radio frequencyenergy transmitted from the base station transceiver antenna. The secondplane is at an angle to the first plane. The second radiating element iselectrically coupled to the first radiating element. The second portionof the radio frequency energy is received at the predetermined operatingfrequency. The method also including processing the received first andsecond portions of the radio frequency energy by the RFID semiconductorchip and generating a reply radio frequency energy at the RFIDsemiconductor chip at a predetermined reply operating frequency. Thegenerating is in response to the processing and in response to the firstand second received radio frequency energy portions. The method furtherincludes radiating the reply radio frequency energy by the first andsecond radiating elements of the antenna coupled to the RFIDsemiconductor chip.

According to another aspect, a method of manufacturing an RFID tagassembly for use in a harsh operating environment includes structuringan antenna electrically coupled to an RFID semiconductor chip having anantenna interface with a conductor. The RFID semiconductor chip operatesat a predetermined operating frequency. The structuring includes formingthe antenna to have a first radiating element lying in a first plane anda second radiating element lying in a second plane at an angle relativeto the first plane. The method includes forming an enclosure having abody defining a cavity with a closed end and an opening. The body isformed from a material that does not conduct or absorb a substantialamount of energy at the predetermined operating frequency. The cavity isdimensioned for receiving and enclosing the RFID semiconductor chip,conductor and structured antenna positioned proximate to the closed endof the cavity. The method also includes mounting the RFID semiconductorchip, conductor and first and second radiating elements of the antennawithin the cavity proximate to the closed end of the cavity and closingthe opening of the cavity containing the RFID semiconductor chip,conductor and antenna. The closing includes sealing the opening.

According to another aspect, an RFID tag assembly for use in tracking ortiming of a progress of a user includes an RFID tag assembly having amounting substrate with an exposed first planar surface and an opposingsecond planar surface. At least one of the first and second planarsurfaces is adapted for selective attachment to an carrier surface. TheRFID tag has an RFID semiconductor chip with a predetermined operatingfrequency and an antenna interface mounted on the at least one of thefirst and second planar surfaces. A conductor is electrically coupled tothe antenna interface of the RFID semiconductor chip and an antenna iselectrically coupled to the conductor. A spacer composed of a foammaterial is attached to the second planar surface. The foam material iscomposed of a material that is non-conducting and non-absorbing of asubstantial amount of energy at the predetermined operating frequency.The spacer is positioned for placement between a surface of the body ofthe user and the RFID tag for positioning at a minimum spaced apartdistance from the surface of the body of the user during operation ofthe RFID tag assembly.

According to another aspect, a method of operating a radio frequencyidentification (RFID) tag assembly includes mounting a mountingsubstrate with an RFID semiconductor chip at a spaced apart distancefrom an operating surface at a distance greater than or equal to about ¼of a wavelength of a predetermined operating frequency of a radiofrequency energy. The operating surface being a surface associated witha body composed of a material that absorbs a substantial amount ofenergy at the predetermined operating frequency. The method alsoincludes receiving at a first side of a two sided planar antenna coupledto an RFID semiconductor chip mounted in proximity to the operatingsurface a first portion of that radio frequency energy as transmittedfrom an antenna associated with a base station transceiver positionedremote from the RFID tag assembly. The first side is oriented away fromthe operating surface. The method further includes receiving at a secondside of the two-sided planar antenna a second portion of the radiofrequency energy transmitted from the base station transceiver antenna.The second portion of the radio frequency energy is received at thepredetermined operating frequency. The second side is oriented towardsthe operating surface. The method also includes processing the receivedfirst and second portions of the radio frequency energy by the RFIDsemiconductor chip. The method further includes generating a reply radiofrequency energy at the RFID semiconductor chip at a predetermined replyoperating frequency in response to the processing and in response to thefirst and second received radio frequency energy portions. The methodincludes radiating the reply radio frequency energy by the first andsecond sides of the two-sided planar antenna.

Further aspects of the present disclosure will be in part apparent andin part pointed out below. It should be understood that various aspectsof the disclosure may be implemented individually or in combination withone another. It should also be understood that the detailed descriptionand drawings, while indicating certain exemplary embodiments, areintended for purposes of illustration only and should not be construedas limiting the scope of the disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side cross-sectional view of a radio frequencyidentification (RFID) tag assembly having a two-radiating elementmulti-plane antenna in relationship to an operating surface according toone exemplary embodiment.

FIG. 2 is a close up side cross-sectional view of an RFID tag assemblyhaving a two-radiating element multi-plane antenna according to oneexemplary embodiment.

FIGS. 3A and 3B are close up side cross-sectional views of two RFID tagassemblies each having a two-radiating element multi-plane antenna inrelationship to an operating surface according to additional exemplaryembodiments.

FIG. 4 is a side cross-sectional view of an RFID tag assembly having atwo-radiating element multi-plane antenna and a reflector inrelationship to an operating surface according to yet another exemplaryembodiment.

FIG. 5 is a close up side cross-sectional view of an RFID tag assemblyhaving a two-radiating element multi-plane antenna and a compositereflector in relationship to an operating surface according to yetanother exemplary embodiment.

FIGS. 6A and 6B are close up side cross-sectional views of two RFID tagassemblies each having a two-radiating element multi-plane antenna andtwo types of reflectors according to additional exemplary embodiments.

FIGS. 7A and 7B are an end cross-sectional view and a sidecross-sectional view of an RFID tag assembly, respectively, each havingan enclosure for mounting according to one exemplary embodiment.

FIGS. 8A and 8B are a top view and an end, respectively, of an enclosuresuitable for use in an RFID tag assembly according to one exemplaryembodiment.

FIGS. 9A to 9E are various views illustrating a method of assembling anRFID tag assembly according to one exemplary embodiment.

FIG. 10 is a side cross-sectional view of an RFID tag assembly having afoam spacer according to yet another exemplary embodiment.

FIG. 11 is a side cross-sectional view of an RFID tag assembly having afoam spacer according to another exemplary embodiment.

FIGS. 12A and 12B are side cross-sectional views of two RFID tagassemblies mounted on a racing bib as a mounting surface and inrelationship to an operating surface according to two additionalexemplary embodiments.

FIG. 13 is a top view of an RFID tag assembly illustrating thedimensions of the RFID tag in relationship to the dimensions of the foaminsert according to one exemplary embodiment.

FIG. 14 is a side cross-sectional view of an RFID tag assembly accordingto another exemplary embodiment.

FIGS. 15A and 15B are front and back perspective views, respectively, oftwo racing bibs as mounting surfaces illustrating placement of the RFIDtag on the front and back of the racing bib according to two additionalexemplary embodiments.

FIG. 16 is a perspective view of an operating environment for an RFIDtag assembly for use in timing the progress of a user in a racing eventaccording to one exemplary embodiment.

FIG. 17 is a block diagram of a specialized computer system suitable forimplementing one or more assembly or methods of various embodiments asdescribed herein.

It should be understood that throughout the drawings, correspondingreference numerals indicate like or corresponding parts and features.

DETAILED DESCRIPTION

The following description is merely exemplary in nature and is notintended to limit the present disclosure or the disclosure'sapplications or uses. For example, the present disclosure generallydescribes various embodiments of an RFID assembly and methods that aresuitable as a “timing chip” for use in timing of participants involvedin a sporting event. However, such application and embodiments are onlyexemplary in nature, and it should be clear to one of skill in the artafter having reviewed the present disclosure, that the RFID assembliesand methods as described herein can be used for any number of other RFIDapplications, including those that require tracking position versus timeor the operation of the RFID assembly in a harsh operating environment.

Before turning to the figures and the various exemplary embodimentsillustrated therein, a detailed overview of various embodiments andaspects is provided for purposes of breadth of scope, context, clarity,and completeness.

In one embodiment, a radio frequency identification (RFID) tag assemblyincluding an RFID semiconductor chip, a conductor and an antenna. TheRFID semiconductor chip as addressed herein can be any radio frequencyidentification chip whether passive or active. The RFID semiconductorstypically have antenna interface, a microprocessor with stored orembedded computer implementable and executable instructions, a memoryfor stored user data, and one or more communication interfaces thatoperate at one or more predetermined operating frequency in receivingand generating radio frequency energy. Any suitable RFID tag can also beused within the scope of the present disclosure. By way of example, theALN-9662 Squiggle-® SH (a registered trademark of Alien Technologies) isone RFIG tag that is suited for use in accordance with the presentdisclosure. Of course other RFID tags are also considered within thescope of the present disclosure.

These RFID semiconductors as implemented as RFID tags can include anyform of communication interface or antenna interface suitable foroperating at the desired or predefined or predetermined operatingfrequency and energy level. Such predetermined operating frequency canbe any frequency suitable for such a desired application, and in oneembodiment, by way of example and not intending to be limited thereto, aUHF spectrum ranging from about 860 to about 928 MHz, and in someembodiments the predetermined operating frequency is in a range about915 MHz. In some embodiments, the predetermined operating frequency maybe a range of operating frequencies wherein the radio frequency energyutilizes two or more operating frequencies for specific functions orapplications, such as, by way of example, one for receiving at the RFIDtag assembly and a second different one for generating and transmittingat the RFID tag. There can be a different one for an initial energypulse or a wake up powering energy communication, a second one for arequest or instruction message, and yet another one for anacknowledgement and/or reply. The discussion herein with regard to suchradio frequency energy includes all such forms of energy. Thecommunication interface is adapted based on predetermined RFIDspecifications and protocols, any of which are generally suitable forapplicability to the described embodiments herein, and this disclosureis not limited to any particular such RFID communication messaging orprotocol or functionality.

For example, a remote RFID transceiver associated with a “RFID Reader”includes a transmitter and receiver (also known as a base station andone or more antennas, collectively referred herein as an RFID basestation transceiver or in short an RFID transceiver. Such remote RFIDtransceiver communicates by generating and receiving radio frequencyenergy at the predetermined operating frequency with various mated RFIDsemiconductor chips for requesting and receiving data stored in a memoryof an RFID semiconductor chip. In some embodiments, the RFID transceivermay also provide an initial radio frequency energy pulse and energytransfer over the predetermined operating frequency. Such radiofrequency energy is received by the RFID semiconductor chip and isstored by the RFID semiconductor chip for powering an embeddedtransceiver, microprocessor, memory, and communication interface,including the antenna interface. Such is typical in a passive RFIDsemiconductor embodiment. As described herein, the radio frequencyenergy includes, and is not limited to, all forms of messaging,signaling, and communications and other methods of radio frequencyenergy transfer.

The components of the various described RFID assemblies can beimplemented as discrete components, or in various groupings, or as anRFID tag that includes two or more of the components mounted on amounting surface of a mounting substrate. For example, the mountingsubstrate can be a non-conductive plastic base, for example a polyester(PET) film (for example, Mylar® that is a registered trademark of DuPontTejjin Films). However, other suitable materials for the mountingsubstrate are also possible and considered within the scope of thepresent disclosure.

The conductor of the RFID assembly is electrically coupled to theantenna interface of the RFID semiconductor chip. The conductor can beany form of electrically conducting material and is often a conductorformed by an integrated circuit fabrication technology resulting in afoil or thin layer conductor on the mounting surface of the mountingsubstrate.

The antenna is electrically coupled to the conductor. The antenna can beany suitable antenna such as, but not limited to, a dipole antenna. Theantenna has a first radiating element lying in a first plane and asecond radiating element lying in a second plane that is at an anglerelative to the first plane. It should be noted that when the antenna isa dipole antenna, the first and second radiating elements are not to beconsidered to be the two opposite direction elements of the dipoleantenna. Rather one or both of the opposing elements of the dipoleantenna can be configured or equipped to having the first and secondangled radiating elements.

The antenna can be a discrete component antenna or can be an antenna asformed by integrated circuit fabrication technology such as a foilantenna having foil radiating elements formed on a mounting surface of amounting substrate, which can be the same mounting substrate asaddressed above. For example, in one embodiment the radiating elementscan be formed from copper foil. In such embodiments, the first andsecond radiating elements of the antenna are formed on the mountingsurface of the mounting substrate as foil radiating elements. An endportion of the mounting substrate along with an end portion of the firstradiating element can be bent or deformed to a position that is angledfrom the first plane containing the remaining portion of the firstradiating element. In this manner, the second radiating element isdifferentiated from the first radiating element by an angled deformationformed in the mounting substrate and the foil antenna. Alternatively,the first radiating element and the second radiating element can beformed by any suitable means including, but not limited to, pre-moldingor pre-casting the second radiating element and the first radiatingelement.

As described above, the second radiating element lies in a second anddifferent plane than the first radiating element. As such, the antennais described herein as a bi-planar antenna. The angle between the twoplanes, radiating element plane 1 and radiating element plane 2 can beany angle, but includes in some embodiments, an angle of between 45degrees and 135 degrees, with one particular embodiment being aperpendicular or 90 degree orientation. Additionally, it should also benoted that the orientation between the two may be either from eitherside of radiating element plane 1.

Each of the radiating elements of the antenna can have any length.However, in one embodiment where the predetermined operating frequencyis in the UHF frequency range of about 902 to about 928 megahertz, thefirst radiating element can have a length less than about ¼ of awavelength of the predetermined operating frequency and the secondradiating element can have a length less than about ¼ of the wavelengthof the predetermined operating frequency. However, other lengths anddimensions of the first and second radiating elements are alsoconsidered within the scope of the present disclosure.

In some embodiments, the RFID assembly as described above can alsoinclude a reflector having a substantially planar reflecting planespaced apart from and substantially parallel to the first plane of thefirst reflecting element. The reflector can be composed of anyreflecting material or components for reflecting some or all of theenergy received at the predetermined operating frequency of the RFIDassembly. The reflector can be positioned apart from the first planewith the reflecting plane positioned towards the first plane on a sideof the first plane of the angled second radiating element or on theopposing side. The reflector can be positioned at any distance from thefirst plane of the first radiating element, or the second radiatingelement. However, in some embodiments, the reflector is positioned apartfrom the first radiating element or at least the first plane of thefirst radiating element with the reflective plane being a distance ofabout ¼ of a wavelength of the predetermined operating frequency. Inother embodiments, the distance can be greater than about ¼ of thewavelength and in some embodiments can be multiples of ¼ of thewavelength.

The reflector can be selected and adapted to not only reflect some orall of the radio frequency energy received at the predeterminedoperating frequency, but also such that the reflector is capacitivelycoupled to the antenna or at least to one of the radiating elementsthereof at the predetermined operating frequency. The capacitivecoupling of the reflector with the spaced apart antenna can provide oneor more benefits to the RFID assembly: act as an amplifier of thereceived radio frequency energy, make the antenna appear and operate ashaving a larger electrical area, increasingly the effective length ofthe antenna beyond the physical length, increase the gain of theantenna, improve the efficiency of the antenna, modify the impedance ofthe antenna, and/or tune or modify the radiation pattern of the antenna.

The reflector can be formed from any type of suitable material or havinga composition of suitable matter. In one embodiment, the reflector is aflat metallic surface that may be ungrounded. In another embodiment, thereflector has a body defining the reflective plane either on the surfaceof the body, or within the surface of the body. For example, the body ofthe reflector can be composed of a composite material having adielectric constant responsive to the predetermined operating frequency.In other embodiments, a composite material for the reflector can includea reflective substance such as metal chips or similar radio frequencyreflecting material. The composite material can be, by way of example, apotting compound. In one embodiment, the potting compound of a reflectorconsists of a 30/70% mix of Loctite® 3173/3183 (Loctite is a registeredtrademark of Henkel AG & Co. KGaA) and has a dielectric constant ofabout 5.92. Other suitable components or compositions can be used toform the reflector, but in some embodiments it may be desired that thedielectric constant of the resulting compound has a dielectric constantin the desired range based on the predetermined operating frequency. Butalso the composition may be selected or adjusted such that thecomposition provides a desired rigidity in its cured form.

In one embodiment, the reflector can consist of a potting compoundhaving a metal flake suspended therein for enhancing the pottingcompound's ability to reflect RF energy. The potting compound can beconfigured to capacitively couple RF energy to the first and secondangled radiating elements of the antenna. The capacitive coupling canprovide for an increase in the effective antenna length that is greaterthan the physical length of the antenna. The amount of capacitivecoupling can be varied by controlling the dielectric constant of thepotting compound and can be used to provide proper tuning of the antennafor the desired operational frequency range. The dielectric constant ofthe potting compound can vary from about 4.68 to about 5.92, dependingon the dimensions of the enclosure, the desired frequency range ofoperation and the amount of capacitive coupling desired. The pottingcompound used for the reflector can also have sufficient rigidity toprotect the RFID assembly components within the enclosure from bothphysical and environmental damage.

In some embodiments, a composite reflector such as one composed from apotting compound, can serve functions for the RFID assembly in additionto the reflecting of the radio energy at the predetermined operatingfrequency. As will be described below, a reflector made from a pottingcompound can be positioned relative to the RFID tag and antenna in amouth or cavity of a mounting configuration such that reflector not onlyacts as a reflector for the radio frequency energy to and from theantenna having the two angled radiating elements, but also to close andseal the mouth or cavity in which it is positioned or formed.

In some embodiments, a spacer can be included that is positioned betweenthe first plane of the first radiating element and the reflector formaintaining the spaced apart position of the reflector from the firstradiating element. Such a spacer can be composed of a material that doesnot conduct or absorb a substantial amount of energy at thepredetermined operating frequency. In some embodiments, the spacer canbe a fixture or mounting of an enclosure of the RFID assembly thatmaintains the reflector distance. In other embodiments, the spacer canbe composed of a foam material and can be attached to the second planarsurface of the mounting substrate, or can be attached to a surface ofthe reflector. Generally, as with any suitable spacer material, the foammaterial of such a spacer should be composed of a material that isnon-conducting and non-absorbing of a substantial amount of energy atthe predetermined operating frequency.

The RFID assembly can also include an enclosure for one or more othercomponents. A suitable enclosure can include a body defining a cavitywith a closed end and an opening. The cavity can be dimensioned forreceiving the mounting substrate, the RFID semiconductor chip, theconductor, and the antenna with the first and second radiating elements.In some embodiments, the mounting substrate can be positioned proximateto the closed end of the cavity, but any suitable position is possibleand considered to be within the scope of the present disclosure.

The size and composition of the enclosure can be optimized for theparticular RFID semiconductor chip, predetermined operating frequency,and antenna, and/or reflector and spacer, where provided. The enclosurecan also be dimensioned for suitable operational considerationsincluding minimizing the overall size and potential drag or exposure ofthe RFID assembly when attached to an operating surface such as aparticipant or vehicle in a timed event. The enclosure can be formedfrom an ABS plastic or any plastic or composite or other material whichprovides sufficient rigidity and minimizes absorption of RF energy. Someplastics contain compounds add strength or color to the plastic, but cannegatively affect the RF energy strength or the RF pattern received andtransmitted by the RFID tag placed inside.

In addition, the enclosure can provide rigidity to minimize the chanceof damage to the internal components when the RFID assembly is used oroperated in harsh conditions. The thickness and dimensions of the wallsof the enclosure can also be optimized to ensure maximum RF energystrength at the RFID tag. The enclosure can include mounting flanges orfixtures that protrude from one or more sides of the enclosure and serveas external operating attachment points for a strap or other devicewhich can be used to attach the RFID assembly to an operating surfacesuch as body of a user or a surface of a vehicle or other user relateddevice. These mounting fixtures can aid in the mounting of the enclosureto an operating surface and, where provided, the reflector can bepositioned between the operating surface and the mounting substrate withthe reflective plane of the reflector being positioned in a directiontowards the mounting substrate and away from the operating surface. Inthis embodiment, the reflector aids in reflecting radio energy thatwould otherwise be absorbed by the body containing the mounting surface.

By way of one exemplary embodiment, a radio frequency identification(RFID) tag assembly includes an RFID semiconductor chip having anantenna interface mounted on a mounting surface of a mounting substrateand has a predetermined operating frequency. The assembly includes aconductor electrically coupled to the antenna interface of the RFIDsemiconductor chip that is mounted on the mounting surface. The assemblyalso includes an antenna that is electrically coupled to the conductor.The antenna has a first radiating element lying in a first plane and asecond radiating element lying in a second plane. The second plane is atan angle relative to the first plane. The first radiating element haslength less than about ¼ of a wavelength of the predetermined operatingfrequency and the second radiating element has a length less than about¼ of the wavelength of the predetermined operating frequency.

In the alternative, another exemplary embodiment can include a radiofrequency identification (RFID) tag assembly having an RFIDsemiconductor chip with an antenna interface mounted on a mountingsurface of a mounting substrate and having a predetermined operatingfrequency. A conductor is electrically coupled to the antenna interfaceof the RFID semiconductor chip and can be formed on the mounting surfaceof the mounting substrate. An antenna is electrically coupled to theconductor and has a first radiating element lying in a first plane andsecond radiating element lying in a second plane, the second plane beingat an angle relative to the first plane. The assembly includes anenclosure having a body defining a cavity with a closed end and anopening. The cavity is dimensioned for receiving the mounting substratewith the RFID semiconductor chip, the conductor, and the first andsecond radiating elements. The mounting substrate is positionedproximate to the closed end of the cavity. The assembly further includesa seal for closing the opening and sealing the cavity.

In another exemplary embodiment, a method of operating a radio frequencyidentification (RFID) tag assembly including receiving at a firstradiating element in a first plane of an antenna coupled to an RFIDsemiconductor chip a first portion of radio frequency energy transmittedfrom an antenna associated with a base station transceiver positionedremote from the RFID tag assembly. The radio frequency energy being at apredetermined operating frequency. The method also including receivingat a second radiating element in a second plane of the antenna coupledto the RFID semiconductor chip a second portion of the radio frequencyenergy transmitted from the base station transceiver antenna. The secondplane is at an angle to the first plane. The second radiating element iselectrically coupled to the first radiating element. The second portionof the radio frequency energy is received at the predetermined operatingfrequency. The method also including processing the received first andsecond portions of the radio frequency energy by the RFID semiconductorchip and generating a reply radio frequency energy at the RFIDsemiconductor chip at a predetermined reply operating frequency. Thegenerating is in response to the processing and in response to the firstand second received radio frequency energy portions. The method furtherincludes radiating the reply radio frequency energy by the first andsecond radiating elements of the antenna coupled to the RFIDsemiconductor chip.

This embodiment of method of operation can also include, as describedabove, reflecting at a reflector a third portion of the radio frequencyenergy at the predetermined operating frequency as transmitted from thebased station transceiver antenna. This can be in addition to any of thefirst and second portions as can be received directly by the first andsecond radiating elements without any reflecting by the reflector. Thereflector can have a substantially planar reflecting plane spaced apartfrom and substantially parallel to at least one of the first and secondplanes of the antenna. The method can also include receiving at thefirst and second radiating elements the third portion of the radiofrequency energy and processing the received third portion of the radiofrequency energy by the RFID semiconductor chip. The reflector can alsoreflect a portion of the generated or radiated predetermined replyenergy as received from one or both of the first and second radiatingelements. As noted above, the predetermined reply operating frequencycan be the same as or different than the predetermined operatingfrequency.

Referring now to the exemplary embodiments as provided by the figures, afirst exemplary embodiment of an RFID tag assembly 10 is shown FIG. 1.An RFID semiconductor chip 12 having an antenna interface 13 is coupledto conductor 14. A mounting substrate 16 having a first surface shown asa mounting surface 15 and an opposing surface 17. An antenna 18 iscoupled to the conductor 14. It should be noted that the RFID tagassembly 10 having only the RFID semiconductor chip 12, conductor 14 andantenna 18 packaged together is often referred to simply as an RFID tag11. As shown in FIG. 1, this exemplary embodiment shows the antenna 18as being a bipolar antenna having two opposing portions 18A and 18B.Each antenna portion 18A and 18B has a first radiating element 20 lyingin a first plane P₁ and a second radiating element 22 lying in a secondplane P₂. An angle α is defined as the angle between the first plane P₁and the second plane P₂. As shown in this example, angle α is about 90degrees and therefore first plane P₁ is perpendicular to second plane P₂and the second radiating element 22 is perpendicular to the firstradiating element 20. In this embodiment, the second radiating element22 is oriented at its angle α to be in the direction of an operatingsurface 24 that is proximate to the RFID tag assembly 10. As shown, theRFID semiconductor chip 12, the conductors 14 and both of the firstradiating elements 20 of each of the poles of the dipole antenna 18 aremounted on the mounting surface 15 of the mounting substrate 16. In thisembodiment, the second radiating elements 22 are shown to extend fromthe first radiating elements 20 at the angle α. The first plane P₁ iseither equivalent to a plane as defined by the mounting surface 15 orparallel thereto. Such first plane P₁ can also be referred to as a firstground plane P₁ and second plane P₂ can also be referenced to as asecond ground plane P2 as would be understood by one of skill in the artafter reviewing the present disclosure.

In operation, the RFID tag assembly 10 is positioned in range of one ormore RFID transceivers T_(R), each with one or more transceiver antennaA_(R). FIG. 1 illustrates two RFID transceivers T_(R1) and T_(R2) eachwith a single transceiver antenna A_(R1) and A_(R2), respectively. Eachantenna A_(R) transmits and receives radio frequency energy E to andfrom the RFID tag assembly 10 at one or more predefined operatingfrequencies B_(OP). For the sake of illustration and discussion,specific energy transmissions are shown as E sub X wherein the X denotesan exemplary propagation of energy between two components solely for thesale of discussion and presentation. One skilled in the art shouldunderstand that this is only for discussion purposes and is not intendedto be limiting or to describe a physical or logical point-to-pointrelationship. Energy E_(RE1) is shown as energy at the predefinedoperating frequency propagating between each of antennas A_(R1) andA_(R2) and the first radiating element 20, e.g., as such thenomenclature wherein X=RE1 for first radiating element. Energy E_(RE2)is similar representative of propagating energy between antennas A_(R1)and A_(R2) and the second radiating element 22. Energy ERE1′ (prime) isshown as propagating between antenna A_(R1) and the first radiatingelement 20 of the far pole of the bipolar antenna 18, but is only shownfor the sake of completeness and should be understood by one skilled inthe art without further explanation. As illustrated here, each of thetwo angled radiating elements receives and transmits energy E_(RE1) thatmay differ from the energy E_(RE2) based on the orientation of eachradiating element 20, 22 with regard to the transceiver antenna A_(R1)or A_(R2). As shown, the more vertical the antenna A_(R1) or A_(R2) iswith regard to plane P₁, the more likely that the first radiatingelement 20 will propagate more energy E_(OP) with the antenna A_(R) thanthe second radiating element 22. Also, the more horizontal the antennaA_(R) is with regard to plane P₁, the more energy E_(OP) will bepropagated with the second radiating element 22 and the less will bepropagated by the first radiating element 20. Of course, as describedabove, the angle α can be something other than 90 degrees and thereforecan be selected based on the expected orientation of the RFID tagassembly 10 with the transceiver antenna A_(R) with which it is expectedto operate in an operating environment.

Also as shown in FIG. 1, the operating surface 24 and/or operating bodyhaving the operating surface 24 will receive a portion of the energyE_(OP) propagated by the transceiver antenna A_(R), as well as thatpropagated by the antenna 18 of the RFID tag assembly 10. However, suchoperating surface 24 often absorbs energy E_(A) into the operatingsurface 24 and therefore can act as a drain on energy E_(OP), or atleast is neutral thereto.

FIG. 2 illustrates another embodiment of an RFID tag assembly 10 that issimilar to that illustrated in FIG. 1 but with some minor differences.In this embodiment, the RFID tag 11 has the mounting substrate 16 isformed continuously in relation to both the first and second radiatingelements 20, 22. As shown, the mounting substrate 16 can define asubstrate plane P_(SS). In other words, the second radiating element 22can also be mounted to the mounting surface 15 of the mounting substrate16. In this embodiment, the mounting substrate 16 is deformed at angleddeformation 26 for define angle α. As shown in FIG. 2, the firstradiating element 20 has a length along first plane P₁ of d_(RE1) andthe second radiating element 22 has a length along second plane P₂ ofd_(RE2). In one embodiment hereof, the lengths d_(RE1) and d_(RE2) canbe different or they can be the same. Such lengths can also be definedin relation to a wavelength of the energy E_(OP) as described above.

FIG. 3A illustrates an embodiment of an RFID tag assembly 10 having theRFID tag 11 formed with the angle α between the second plane P₂ and thefirst plane P₁ being greater than 90 degrees in the direction ororientation of the operating surface 24 and therefore typically in theopposing direction of the placement of the transceiver antenna AR. FIG.3B illustrates an embodiment of an RFID tag assembly 10 having the RFIDtag 11 formed with the angle α between the second plane P₂ and the firstplane P1 being greater than 90 degrees but in the direction ororientation away from the operating surface 24 and therefore typicallyin a direction towards the typical placement of the transceiver antennaA_(R). In both these embodiments, the mounting substrate 16 is shown asextending proximate to both the first and second radiating elements 20,22 wherein the deformation 26 defines the angle α and thedifferentiating point between the first radiating element 20 in thefirst plane P₁ and the second radiating element 22 in the second planeP₂.

FIG. 4 illustrates another exemplary embodiment of an RFID tag assembly30 having a two-radiating element angled multi-plane antenna 18 and areflector 32 positioned between the RFID tag 11 and the operatingsurface 24. In this exemplary embodiment, the reflector 32 has body 34that is composed of a composite material with a reflective surface 38defining a reflective plane P_(R). The reflective surface 38 is selectedfor optimizing the reflection of energy E_(OP) at the predeterminedoperating frequency. The reflector 32 is positioned relative to the RFIDtag 11 and the operating surface 24 at a distance D_(RF) from the RFIDtag 11 or at least the first plane P₁ of the first radiating elementR_(E1). The distance D_(RF) is selected as a function of the wavelengthof the predetermined operating frequency as described above. Forexample, in one exemplary embodiment, the distance D_(RF) can be betweenabout 6 millimeters (about 0.250 inches) and about 7 millimeters (about0.275 inches).

The operation of RFID tag assembly 30 is similar to that described abovewith regard to FIGS. 1-3, except with regard to the reflected energyE_(RF) that is received from either the transceiver antenna A_(R1),A_(R2) or the first or second radiating elements 20, 22. The reflector32 can operate to prevent absorption of the operating energy E_(OP) bythe operating surface 24 in the area proximate to the RFID tag assembly30 and/or to reflect a portion of the E_(OP) as reflected energy E_(RF)that propagates between the transceiver antenna A_(R) and one or both ofthe first and second reflecting elements 20, 22.

FIG. 5 illustrates another embodiment of the RFID tag assembly 30. Inthis embodiment, the RFID tag assembly 30 has a reflector 32 that hasthe body 34 composed of a composite material containing reflectivematerial 36 such as metal flakes, by way of example. This differs alsofrom the embodiment of FIG. 4 in that the reflector 32 does not includea reflective surface 38. As the composite material of the body 34 of thereflector 32 with the embedded reflective material 36 provides thereflective characteristics of the reflector 32, the reflective planeP_(RF) is effectively below an exposed surface of the reflector and lieswithin the body 34. As such, the distance D_(RF) should be adjusted tooptimize the positioning between the reflector 32 and first reflectingelement 20 or at least the first plane P₁. FIG. 5 also illustrates thatthe reflector 32 may be positioned apart from the operating surface 24and the plane of the operating surface P_(S). The spaced apart positionof the reflector 32 from the operating surface 24 results in a gapidentified by distance d_(OS).

FIGS. 6A and 6B reflect two alternative embodiments to the RFID tagassembly 30. FIG. 6A illustrates the relationship between and theorientation of the reflector 32 and the RFID tag 11 where the secondradiating element 22 extends towards the reflector 32 but at an angle αthat is greater than 90 degrees. As shown, the reflector 32 includes thereflecting surface 38 and is positioned at a distance d_(RF) from thefirst plane P₁. FIG. 6B illustrates an exemplary embodiment wherein thereflector 32 is a composite reflector with reflecting elements 36embedded therein. As shown, the RFID tag 11 has the second radiatingelement 22 extending away from reflector 32 at an angle α that isgreater than 90 degrees in this exemplary embodiment.

FIGS. 7A and 7B illustrate an exemplary embodiment of an RFID tagassembly 50 wherein the RFID tag assembly 30 is enclosed in an enclosure51. FIG. 7A is an end cross-sectional view and FIG. 7B is a sidecross-sectional view. As shown, the enclosure 51 is defined by a body 52having a plurality of walls 54 defining an opening 56, and a cavity 58.One of the walls 54 is an end wall 57 at an end of the cavity 58opposing the opening 56. The opening 56 and the cavity 58 aredimensioned for receiving and holding an RFID tag 11 such as one or moreRFID tag assemblies 10. As shown, the body 52 can also include one ormore mounting fixtures 64 for mounting of the enclosure to an operatingsurface 24. FIGS. 8A and 8B are a top view and an end, respectively, ofone suitable enclosure 51 for use in RFID tag assembly 50.

As shown in the exemplary embodiment of FIGS. 7A, 7B and 8A and 8B, theRFID tag assembly 50 can have the RFID tag 11, or tag assembly 10, 30,positioned within the cavity 58. As shown, the RFID tag 11 can bepositioned proximate to the end wall 57. The RFID tag 11 can be mountedto the end wall 57 by an adhesive (not shown) or can be otherwisesecured into place or place for biasing against the end wall 57 that caninclude a mounting material therebetween as required. A reflector 32 canbe positioned at the distance d_(RF) from the RFID tag 11 and inparticular from the first plane P₁. A seal 60 is provided for closingthe opening 56 and securing and sealing the RFID tag within the cavity58. The seal 60 can provide a waterproof seal protecting the RFID tag11. In some embodiments, the reflector 32 can be composed of a compositeor other material that can act not only as a portion of the reflector 32but also as the seal 60. For example, the reflector 32 can be composedof a potting material as described above. The potting material is placedin the opening 56 to form the reflector 32 and also provides the seal 60once the potting material cures. Additionally, a reflective surface 38can be included in some embodiments. Also, in some embodiments, a spacer62 can be included for providing the continued spaced apart position ofthe RFID tag 11 from the reflector 32 and/or other the seal. The spacer62 can be any spacer or made of any material as described above.Additionally, in some embodiments the spacer 62 can be configured as anintegrally portion or fixture of the walls 54 as inside a portion of thecavity 58. The height of the spacer can be of any length, but in oneembodiment is at least about 3 millimeters (about 0.125 inches).

In another embodiment, a method of manufacturing an RFID tag assemblyfor use in a harsh operating environment includes structuring an antennaelectrically coupled to an RFID semiconductor chip having an antennainterface with a conductor. The RFID semiconductor chip operates at apredetermined operating frequency. The structuring includes forming theantenna to have a first radiating element lying in a first plane and asecond radiating element lying in a second plane at an angle relative tothe first plane. The method includes forming an enclosure having a bodydefining a cavity with a closed end and an opening. The body is formedfrom a material that does not conduct or absorb a substantial amount ofenergy at the predetermined operating frequency. The cavity isdimensioned for receiving and enclosing the RFID semiconductor chip,conductor and structured antenna positioned proximate to the closed endof the cavity. The method also includes mounting the RFID semiconductorchip, conductor and first and second radiating elements of the antennawithin the cavity proximate to the closed end of the cavity and closingthe opening of the cavity containing the RFID semiconductor chip,conductor and antenna. The closing includes sealing the opening.

In one embodiment, the method of manufacturing includes structuring theantenna by modifying an RFID tag assembly formed on a mounting substratehaving the RFID semiconductor chip, conductor and a preformed planarfoil antenna formed thereon. The preformed antenna lies in the firstplane and has a length equal to or greater than about ½ of a wavelengthof the predetermined operating frequency. The method includes cutting anend portion of the mounting surface and the preformed antenna formedthereon to form a reduced length antenna having a length of the antennato less than about ½ of the wavelength of the predetermined operatingfrequency. An end of the reduced length antenna is deformed at the angleto form an angled deformation between the second radiating elementdefined at the end of the antenna and the first radiating element beinga portion of the reduced length antenna that is not deformed. The firstand second radiating elements are therefore formed to each having alength of less than about ¼ of the wavelength of the predeterminedoperating frequency. As noted above, this process can be repeated ateach opposing element of a bipolar antenna wherein applicable. The otheraspects of the manufacturing process of embodiments of the RFID assemblyare inherent above in the description of the RFID assembly.

FIG. 9 (illustrated as FIGS. 9A-9E) provides a pictorial representationof one exemplary method of manufacturing an RFID tag assembly 50. As aninitial step, while not shown, a pre-manufactured OEM RFID tag 11 havingthe RFID semiconductor ship 12, conductors 14 and bipolar antenna 18formed on a mounting surface 15 of a mounting substrate 16 is modified.Each end of the mounting substrate 16 includes one of the poles of thebipolar antenna 18. The mounting substrate 16 as provided defines thefirst plane P₁. Each opposing end of the mounting substrate 16 and aportion of each pole of the bipolar antenna 18 are cut and shortenedsuch that each remaining antenna length is less than about ½ of thewavelength of the predetermined operating frequency. Next, eachshortened end of the mounting substrate 16 is deformed at a point so asto create the deformation point 26 and to form the separation betweenthe first radiating element 20 in the first plane P₁ and the secondradiating element 22 as well the second plane P₂ and the angle αtherebetween. In some embodiments, the second radiating element 22 canbe dimensioned to have a length of about 3 millimeters (0.125 inches)and the first radiating element 20 has a length of about 6 millimeters(0.25 inches). Of course other dimensions are also possible as describedabove. As such, an embodiment of the RFID tag assembly 10 is formed.

As shown in FIGS. 9A and 9B, the RFID tag assembly 10 is placed throughopening 56 and against the end wall 57 of the cavity with the firstexposed surface 17 of the mounting substrate 16 being in the directionof the end wall 57 and the mounted RFID tag 11 being in the direction ofthe opening 56. The enclosure 51 and its cavity 58 can be sized so thatthe RFID tag 11 remains at least 10 millimeters (0.39 inches) away fromany wall 54 of the cavity 58. As shown in this example, each of thesecond radiating elements 22 is positioned proximate to a side wall 54of the enclosure within the cavity 58 and in the direction ororientation of the opening 56. The first exposed surface 17 can befixedly or selectively attached to the end wall 57 with an adhesive insome embodiments. In another embodiment, the second radiating element 22can be secured to the side wall 54 of the cavity 58 using anon-conductive adhesive or similar fastener. FIG. 9B provides a top viewof the RFID tag assembly 10 being positioned within the cavity 58 ofenclosure 51.

By placing the first and second radiating elements 20, 22 at each end ofthe cavity 58 as shown in FIG. 9B, the RFID tag assembly 50 can functionequally well in any orientation relative to antennas A_(R) associatedwith the remote RFID transceiver T_(R). An effective length of radiatingelements 20 and 22 can be adjusted based on the wavelength of thepredetermined operating frequency. The length d_(RE1) of the firstradiating element 20 and/or length of d_(RE2) of the second radiatingelement 22 can be varied to accommodate operation in other frequencyranges.

Next, as shown in FIG. 9C, a spacer 62 is placed through the opening 56and into the cavity 58 overlaying the placed RFID tag assembly 10. Asdescribed above, the spacer 62 can be configured and/or dimensioned toprovide a predefined spacing either between a reflector 32 (whereincluded), or in relation to an operating surface 24 on which theenclosure 51 is placed or mounted. In the embodiment of FIG. 9C, thecavity 58 is dimensioned so as to accept not only the spacer 62 but alsoa reflector 32. After the spacer 62 is inserted as in FIG. 9C, thereflector 32 can be placed in the opening 56 such as by placing anuncured potting material of body 34 on top of the spacer 62 proximate tothe opening 56 and about to the end of the walls 54 defining the cavity58 and the opening 56. This is shown in FIG. 9D. Also, in someembodiments, as in FIG. 9D, a reflective material 36 may be added tomaterial of the body 34. In the alternative, a reflective surface 38 orcomponent or structure providing the reflective surface 38 can be placedproximate to the spacer 62 prior to the placement of the reflector 32.The potting compound of the reflector 32 can provide a seal 60 to theopening 56 and the cavity 58. However, in other embodiments, an exteriorseal 60 can be added after placement of the reflector 32 as shown inFIG. 9E for providing a desired seal and protection to the reflector 32and to the RFID tag assembly 50.

In another embodiment, an RFID tag assembly for use in tracking ortiming of a progress of a user includes an RFID tag having a mountingsubstrate with an exposed first planar surface and an opposing secondplanar surface. At least one of the first and second planar surfaces isadapted for selective attachment to an carrier surface. The RFID tag hasan RFID semiconductor chip that is any type of RFID chip and can have apredetermined operating frequency and an antenna interface mounted onthe at least one of the first and second planar surfaces. A conductor iselectrically coupled to the antenna interface of the RFID semiconductorchip and an antenna is electrically coupled to the conductor. As shown,the antenna can be a bipolar foil antenna. The RFID semiconductor chipand the conductor can each be formed on the mounting surface of themounting substrate. Similarly, the antenna can be formed on one of thesurfaces of the mounting substrate as a foil antenna. The mountingsubstrate can be any suitable mounting material including a polyester(PET) film.

A spacer composed of a foam material is attached to the second planarsurface. The foam material is composed of a material that isnon-conducting and non-absorbing of a substantial amount of energy atthe predetermined operating frequency. The spacer can be positioned forplacement between a surface of the body of the user and the RFID tag forpositioning at a minimum spaced apart distance from the surface of thebody of the user during operation of the RFID tag assembly. The spacercan be attached to the first or second planar surface of the mountingsubstrate by an adhesive material or as otherwise suitable for theapplication. The spacer can be dimensioned to have a spaced apartdistance between the operating surface of the body of the user and themounting substrate that is greater than or equal to about ¼ of awavelength of the predetermined operating frequency. For example, in oneexemplary embodiment the spacer is dimensioned to have a spaced apartdistance between a surface of the user body and the mounting substrateof between about 0.125 inches and about 0.5 inches.

The mounting substrate of the RFID tag assembly can be a substantiallyplanar mounting substrate having a length, a width and a thickness. Thethickness of the mounting substrate can be the distance between thefirst planar surface and the opposing second planar surface. The lengthof the spacer can be a length and width that is substantially equal toor greater than the length and width of the RFID tag assembly mountingsubstrate, respectively. As such, the spacer can encircle or enclose themounting substrate. An example of an RFID tag assembly 80 is shown inFIG. 13. As shown, the length of the spacer L_(SP) is greater than thelength of the mounting substrate L_(MS) and the height of the spacerH_(SP) is greater than the height of the mounting substrate H_(MS).

The assembly can also include a mounting body having the carrier surfacethereon. The carrier surface can be composed of a non-permeable materialand the at least one planar surface is attached to the carrier surface.In such embodiments, the spacer can also be composed of a waterproofnon-permeable foam material, such as a high density foam material. Assuch, the attached spacer and attached carrier surface can provide asubstantially moisture proof sealing of the RFID tag assembly fromexternal foreign substances and moisture. The sizing of the spacer andthe carrier surface can ensure that the RFID tag assembly is completelyenclosed and protected. For example, a race bib can be provided as amounting body for selective attachment of the RFID tag assembly to abody of a user or vehicle. The race bib can have a front planar surfacefor placement outward from the user body or operating surface and anopposing back planar surface for placement proximate to and in thedirection of the user body or operating surface. The carrier surface canbe the front or the back planar surfaces of the race bib. The firstplanar surface of the mounting substrate can be attached to the backsurface of the race bib with an adhesive material and the spacer can beattached to the front surface of the race bib with an adhesive material.The adhesive material can be attached to the first planar surface of themounting substrate for selective attachment of the assembly to a surfaceof a carrier, i.e., a carrier surface.

In another embodiment, a method of operating a radio frequencyidentification (RFID) tag assembly includes mounting a mountingsubstrate with an RFID semiconductor chip at a spaced apart distancefrom an operating surface at a distance greater than or equal to about ¼of a wavelength of a predetermined operating frequency of a radiofrequency energy. The operating surface being a surface associated witha body composed of a material that absorbs a substantial amount ofenergy at the predetermined operating frequency. The method alsoincludes receiving at a first side of a two sided planar antenna coupledto an RFID semiconductor chip mounted in proximity to the operatingsurface a first portion of that radio frequency energy as transmittedfrom an antenna associated with a base station transceiver positionedremote from the RFID tag assembly. The first side is oriented away fromthe operating surface. The method further includes receiving at a secondside of the two-sided planar antenna a second portion of the radiofrequency energy transmitted from the base station transceiver antenna.The second portion of the radio frequency energy is received at thepredetermined operating frequency. The second side is oriented towardsthe operating surface. The method also includes processing the receivedfirst and second portions of the radio frequency energy by the RFIDsemiconductor chip. The method further includes generating a reply radiofrequency energy at the RFID semiconductor chip at a predetermined replyoperating frequency in response to the processing and in response to thefirst and second received radio frequency energy portions. The methodincludes radiating the reply radio frequency energy by both the firstside and the second side of the two-sided planar antenna.

Referring to the two exemplary embodiments of FIGS. 10 and 14, an RFIDtag assembly 80 includes an RFID tag 11 includes an RFID semiconductorchip 12 with an antenna interface (not shown), a conductor 14 and abipolar antenna 18, which is shown as two first radiating elements 20,and a mounting substrate 16 that has a first surface 82 and a secondsurface 84. The RFID semiconductor chip 12, conductor 14 and two firstradiating elements 20 are each mounted on the second surface 84. A foamspacer 62 is attached to the second surface 15 and about the mountedRFID semiconductor chip 12, conductor 14, and two first radiatingelements 20. The spacer 62 can have a thickness such as a minimumthickness of d_(min) such that the spacer spaces the two first radiatingelements 20 apart from the surface plane P_(S) of an operating surface24. However, in some embodiments, d_(min) can be the sum of thethickness of the spacer, and any other expected nonconductive materialthat is expected to be present between the first plane P1 containing thefirst radiating elements and the operating surface. As such, thethickness of the spacer can be less than the ¼ wavelength or the totald_(min) in some embodiments.

In operation, as illustrated by example in FIG. 11, operating energyE_(OP) is propagated between a transceiver antenna A_(R1) and one orboth of the first radiating elements 20. As shown in this embodiment,there is no carrier or attachment surface. This includes directpropagated energy E_(D) and indirect propagated energy E_(IN). As shown,the amount of indirect propagated energy E_(IN) can be enhanced bydimensioning of the spacer thickness d_(min). This can also includereducing the absorption of the indirect propagated energy E_(IN) by thespaced apart positioning caused by the spacer thereby limiting thenegative effect of energy absorption by the operating surface 24.

In another embodiment, as shown in FIG. 12A, the RFID tag assembly 10 isattached to a carrier 86 that has a front planar surface 89 and anopposing carrier surface 87. The RFID tag assembly 10 is attached by anadhesive (not shown) that is one the first surface 17 of the mountingsubstrate 16 that is opposite of the second surface 15 on which the RFIDtag assembly components are mounted. The spacer 62 is attached as in theembodiment of FIG. 11 and has an outer surface 88 that is positioned forengagement against the operating surface 24 for ensuring that theminimum distance d_(min) is maintained during operation.

FIG. 12B illustrates another embodiment where with the carrier 86 beingpositioned between the RFID tag assembly 10 and the operating surface24. In this embodiment, the spacer 62 is attached similarly to thatdescribed in FIGS. 10 and 11; however, the outer surface of the spacer62 is attached to the outer surface 89 of the carrier 86 rather than theopposing carrier surface 87. In this manner, the thickness of thecarrier and the thickness of the spacer 62 combine to provide forensuring the minimum distance d_(min) is maintained.

FIGS. 15A and 15B provide illustrations of two exemplary embodiments ofa racing bib 90 having a front exposed surface 92 with indicia 93 thatis typical of a racing bib. A back or opposing surface 94 is alsoprovided. FIG. 15A illustrates the placement of the RFID tag assembly 80on the front exposed surface 92 and FIG. 15B illustrates the placementof the RFID tag assembly 80 on the opposing surface 94.

FIG. 16 is a perspective view of an operating environment for an RFIDtag assembly 80 such as for timing the progress of a user in a racingevent using a racing bib 90 as illustrated in FIG. 15A or 15B, by way ofexamples. As shown, the racing bib 90 is worn by the user whom isrunning along track 102 and approaching timing point 104. Timing point104 may be any timing point and can include a finish line of track 102.Transceiver antenna A_(R1) and A_(R2) are mounted proximate to thetiming point 104 for exchanging operating energy E_(OP) with the RFIDtag assembly 80 mounted on the bib 90.

Referring to FIG. 17, an operating environment for an illustratedembodiment of the an RFID semiconductor chip and/or remote transceiveris a computer system 300 with a computer 302 that comprises at least onehigh speed processing unit (CPU) 304, in conjunction with a memorysystem 306 interconnected with at least one bus structure 308, an inputdevice 310, and an output device 312. These elements are interconnectedby at least one bus structure 308. As addressed above, the input andoutput devices can include a communication interface including anantenna interface.

The illustrated CPU 304 for an RFID semiconductor chip is of familiardesign and includes an arithmetic logic unit (ALU) 314 for performingcomputations, a collection of registers for temporary storage of dataand instructions, and a control unit 316 for controlling operation ofthe computer system 300. Any of a variety of processors, including atleast those from Digital Equipment, Sun, MIPS, Motorola, NEC, Intel,Cyrix, AMD, HP, and Nexgen, is equally preferred but not limitedthereto, for the CPU 304. The illustrated embodiment of the inventionoperates on an operating system designed to be portable to any of theseprocessing platforms.

The memory system 306 generally includes high-speed main memory 320 inthe form of a medium such as random access memory (RAM) and read onlymemory (ROM) semiconductor devices that are typical on an RFIDsemiconductor chip. However, the present disclosure is not limitedthereto and can also include secondary storage 322 in the form of longterm storage mediums such as floppy disks, hard disks, tape, CD-ROM,flash memory, etc. and other devices that store data using electrical,magnetic, and optical or other recording media. The main memory 320 alsocan include, in some embodiments, a video display memory for displayingimages through a display device (not shown). Those skilled in the artwill recognize that the memory system 306 can comprise a variety ofalternative components having a variety of storage capacities.

Where applicable, while not typically provided on RFID tags or chips, aninput device 310, and output device 312 can also be provided. The inputdevice 310 can comprise any keyboard, mouse, physical transducer (e.g. amicrophone), and can be interconnected to the computer 302 via an inputinterface 324 associated with the above described communicationinterface including the antenna interface. The output device 312 caninclude a display, a printer, a transducer (e.g. a speaker), etc, and beinterconnected to the computer 302 via an output interface 326 that caninclude the above described communication interface including theantenna interface. Some devices, such as a network adapter or a modem,can be used as input and/or output devices.

As is familiar to those skilled in the art, the computer system 300further includes an operating system and at least one applicationprogram. The operating system is the set of software which controls thecomputer system's operation and the allocation of resources. Theapplication program is the set of software that performs a task desiredby the user, using computer resources made available through theoperating system. Both are typically resident in the illustrated memorysystem 306 that may be resident on the RFID semiconductor chip.

In accordance with the practices of persons skilled in the art ofcomputer programming, the present invention is described below withreference to symbolic representations of operations that are performedby the computer system 300. Such operations are sometimes referred to asbeing computer-executed. It will be appreciated that the operationswhich are symbolically represented include the manipulation by the CPU304 of electrical signals representing data bits and the maintenance ofdata bits at memory locations in the memory system 306, as well as otherprocessing of signals. The memory locations where data bits aremaintained are physical locations that have particular electrical,magnetic, or optical properties corresponding to the data bits. Theinvention can be implemented in a program or programs, comprising aseries of instructions stored on a computer-readable medium. Thecomputer-readable medium can be any of the devices, or a combination ofthe devices, described above in connection with the memory system 306.

By way of one exemplary embodiment, a multi-ground plane UHF energizedRFID assembly as included in the disclosure can improve the performanceof an RFID tag when it is being used in a harsh environment such as forthe purposes of timing participants in sporting, or similar, events. Insome embodiments, the RFID assembly can provide a small form factor,minimal drag, protection from harsh environments and potential damage,extended read distances up to 5.5 meters (18 feet), and additionalspacing between an RFID tag and a surface on which it is mounted, suchas the human body. The RFID assembly can be designed to operate attemperatures from about 29° C. (−20° F.) to about 60° C. (140° F.) anddepths of up to about 2.74 meters (9 feet). As described, in someembodiments such an RFID assembly can include a compressed foldedmulti-ground plane dipole antenna for transmitting and receiving RFenergy coupled to the RFID tag. In such a passive timing chip, thereceived RF energy powers the RFID tag.

As known to those skilled in the art after reviewing this disclosure,the dimensions and deformation angle, and the antenna and reflector andspacer components can provide an optimization of the RF pattern. Suchoptimization can improve the strength of the energy at the predeterminedoperating frequency received by the RFID semiconductor chip, generatedby the RFID assembly, and received by the remote transceiver. Asdiscussed, some of or all of the improvements in the transmitted andreceived energy strength occurs in part due to the interaction of a baseground plane component or radiating element in the first plane and theangled ground plane component or radiating element in the second plane.The RFID tag assembly can also be optimized for operation over aspecific range of frequencies. In some of the embodiments, the antennacan be optimized for the UHF spectrum ranging from 902 to 928 megahertz,but can function satisfactorily down to 865 megahertz. In addition tothe RFID tag assembly, in some embodiments, the RFID assembly includes afoam-core non-conductive spacer, and a reflector that are used toenhance the performance of the tag. The multi-ground planes inconjunction with the spacer can provide for minimizing the effect of theabsorption of the RF energy by a human body that is in close proximityto the RFID assembly.

The RFID assemblies of the present disclosure, in one or more embodimentas disclosed herein, or as otherwise implemented, can provide one ormore of a number of advantages over existing RFID tag solutions commonlyused in harsh operating environments such as, for example, the field ofsports timing. By way of just one example, the described integration ofthe components including a hardened plastic enclosure, a compressedfolded multi-ground plane dipole antenna, a rigid foam-corenon-conductive spacer, and a reflector can provide a unique solutionthat meets the needs of many types of events, including sporting eventssuch as triathlons, adventure races, motocross, and mountain bike races,to name a few. The other embodiments and variations of the RFID assemblyas described herein can provide similar benefits and operating use ofRFID assemblies.

When describing elements or features and/or embodiments thereof, thearticles “a”, “an”, “the”, and “said” are intended to mean that thereare one or more of the elements or features. The terms “comprising”,“including”, and “having” are intended to be inclusive and mean thatthere may be additional elements or features beyond those specificallydescribed.

Those skilled in the art will recognize that various changes can be madeto the exemplary embodiments and implementations described above withoutdeparting from the scope of the disclosure. Accordingly, all mattercontained in the above description or shown in the accompanying drawingsshould be interpreted as illustrative and not in a limiting sense.

It is further to be understood that the processes or steps describedherein are not to be construed as necessarily requiring theirperformance in the particular order discussed or illustrated. It is alsoto be understood that additional or alternative processes or steps maybe employed.

What is claimed is:
 1. A method of operating a radio frequencyidentification (RFID) tag assembly in a timed sporting event using anRFID tag reader and timing system for determining a lapse time of aparticipant carrying the tag assembly, the tag assembly having awavelength of a predetermined operating frequency of a radio frequencyenergy comprising: in the radio frequency identification (RFID) tagassembly positioned in proximity to an operating surface of a bodycomposed of a radio frequency absorbing material, the tag assemblyreceiving the radio frequency energy at the predetermined operatingfrequency as transmitted by a remotely positioned antenna of a basestation transceiver and having a substrate having a first planar surfaceand an opposing second planar surface, a passive RFID chip, a two sidedplanar antenna and a spacer, the receiving including receiving by thetwo sided planar antenna having a first side oriented away from theoperating surface of the body and having a second side opposing thefirst side and oriented towards the operating surface of the body, thereceiving at the second side being through a spacer having a thicknessof between about 0.125 inches and about 0.5 inches that is mounted tothe second surface of the substrate and being composed of non-conductingthat is also non-absorbing material of a substantial amount of radiofrequency energy at the predetermined operating frequency; placing theRFID tag assembly in a position relative to the operating surface of thebody that the second side of the two sided planar antenna is a minimumspaced apart distance; receiving at the first side of the two sidedplanar antenna a first portion of the radio frequency energy as directenergy as transmitted from the antenna of the base station transceiver;receiving at the second side of the two-sided planar antenna a secondportion of the radio frequency energy as indirect energy as transmittedfrom the antenna of the base station transceiver, the receiving of thesecond portion being responsive to the absorbing of the substantialamount of radio frequency energy by the absorbing material of the secondside, said second portion of the radio frequency energy being receivedat the predetermined operating frequency; and processing the receivedfirst and second portions of the radio frequency energy by the RFIDsemiconductor chip.
 2. The method of claim 1 wherein the predeterminedoperating frequency is a frequency within a UHF frequency band the stepof positioning is at the minimum spaced apart distance of greater than0.5 inches.
 3. The method of claim 1 wherein the predetermined operatingfrequency is a frequency within a UHF frequency band.
 4. The method ofclaim 1, further comprising positioning the RFID assembly between theoperating surface of the body and a carrier and mounting the RFIDassembly on a carrier surface of the carrier at the minimum spaced apartdistance of greater than about 0.5 inches during operating of the RFIDtag in the timed event.
 5. The method of claim 4 wherein the carrier isa race bib and wherein the carrier surface is the a back planar surfaceof the race bib, further comprising attaching the first planar surfaceof the mounting substrate to the back planar surface of the race bibwith an adhesive material.
 6. The method of claim 4 wherein the carriersurface is composed of a non-permeable material and the spacer iscomposed of a waterproof non-permeable foam material, further comprisinga substantially moisture proof sealing of the RFID tag assembly fromexternal foreign substances and moisture by the mounting of the RFIDassembly on the carrier surface of the carrier.
 7. The method of claim 1wherein the second portion of the radio frequency energy is responsiveto the body performing the absorbing by passively absorbing thesubstantial amount of energy after the received energy first passesthrough the spacer that is composed of a high density foam material andprior to the second portion of radio frequency energy being received bythe second side of the two-sided planar antenna.
 8. The method of claim1, further comprising attaching the first planar surface of thesubstrate to a back surface of a race bib of a participant user in arace with an adhesive material.
 9. The method of claim 8 wherein theattaching includes the thickness of the spacer being selectivelydimensioned to form the spaced apart distance between the operatingsurface of the body of the participant user and the second side of thetwo sided planar antenna of greater than about 0.5 inches.
 10. Themethod of claim 1, further comprising coupling the RFID chip to thesecond surface of the substrate and then attaching the spacer over thecoupled RFID chip and the second surface of the substrate.
 11. Themethod of claim 1 wherein the two sided planar antenna is a bipolar foilantenna with to opposing radiating elements formed on one of thesurfaces of the substrate.
 12. The method of claim 1 wherein the RFIDsemiconductor chip and the two sided planar antenna comprises a bipolarfoil planar antenna formed on the second surface of the substrate. 13.The method of claim 1, further comprising: generating a reply radiofrequency energy at the RFID semiconductor chip at a predetermined replyoperating frequency in response to the receiving and processing of thefirst and second received radio frequency energy portions; and radiatingthe generated reply radio frequency energy from at least one of thefirst side and the second side of the two-sided planar antenna.
 14. Themethod of claim 1, further comprising mounting the spacer to the secondsurface of the substrate containing the RFID chip and the two sidedplaner antenna, the mounting enclosing the substrate within the spacer.15. The method of claim 1 wherein the substrate has a length and a widthand the spacer has a length equal to or substantially greater than thelength of the substrate and a width equal to or substantially greaterthan the length of the substrate, further comprising mounting the spacerto the second surface of the substrate containing the RFID chip and thetwo sided planer antenna, the mounting enclosing the substrate by thespacer.
 16. The method of claim 1 wherein the spacer is composed of awaterproof non-permeable high density foam material.
 17. The method ofclaim 1 wherein the received second portion of the radio frequencyenergy as indirect energy is responsive to a reduction in thesubstantial amount of radio energy absorbed in the absorbing process asprovided by placing at the minimum spaced apart distance as at leastpartially defined by the thickness of the spacer.
 18. A method ofoperating a radio frequency identification (RFID) tag assembly in atimed sporting event using an RFID tag reader and timing system fordetermining a lapse time of a participant carrying the tag assembly, thetag assembly having a radio frequency energy and a wavelength of apredetermined operating frequency in the UHF frequency band: providingthe radio frequency identification (RFID) tag assembly positioned inproximity to an operating surface of a body, the tag assembly capable ofreceiving the radio frequency energy at the predetermined operatingfrequency as transmitted by a remotely positioned antenna of a basestation transceiver and having a substrate having a first planar surfaceand an opposing second planar surface, an RFID chip, a two sided planarantenna and a spacer, the two sided planar antenna having a first sideoriented away from the operating surface of the body and a second sideopposing the first side and oriented towards the operating surface ofthe body, the spacer mounted to the second surface of the substrate andbeing composed of non-conducting material having a thickness of betweenabout 0.125 inches and about 0.5 inches and that is non-absorbing of asubstantial amount of radio frequency energy at the predeterminedoperating frequency; placing the RFID tag assembly in a positionrelative to the operating surface of the body that the second side ofthe two sided planar antenna is a minimum spaced apart distance ofgreater than about 0.5 inches; receiving at the first side of the twosided planar antenna a first portion of the radio frequency energy asdirect energy as transmitted from the antenna of the base stationtransceiver; receiving at the second side of the two-sided planarantenna a second portion of the radio frequency energy as indirectenergy as transmitted from the antenna of the base station transceiverresponsive to an absorbing of the substantial amount of radio frequencyenergy by an absorbing material body, said second portion of the radiofrequency energy being received at the predetermined operatingfrequency; processing the received first and second portions of theradio frequency energy by the RFID semiconductor chip; generating areply radio frequency energy at the RFID semiconductor chip at apredetermined reply operating frequency in response to the receiving andprocessing of the first and second received radio frequency energyportions; and radiating the generated reply radio frequency energy fromat least one of the first side and the second side of the two-sidedplanar antenna.